Source for java.lang.management.OperatingSystemMXBean

   1: /* OperatingSystemMXBean.java - Interface for an operating system bean
   2:    Copyright (C) 2006 Free Software Foundation
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: package java.lang.management;
  39: 
  40: /**
  41:  * Provides access to information about the underlying operating
  42:  * system.  An instance of this bean is obtained by calling
  43:  * {@link ManagementFactory#getOperatingSystemMXBean()}.
  44:  *
  45:  * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
  46:  * @since 1.5
  47:  */
  48: public interface OperatingSystemMXBean
  49: {
  50: 
  51:   /**
  52:    * Returns the name of the underlying system architecture.  This
  53:    * is equivalent to obtaining the <code>os.arch</code> property
  54:    * via {@link System#getProperty(String)}.
  55:    *
  56:    * @return the name of the underlying system architecture on which
  57:    *         the VM is running.
  58:    * @throws SecurityException if a security manager exists which
  59:    *                           prevents access to the name property.
  60:    * @see java.lang.System#getProperty(String)
  61:    * @see java.lang.SecurityManager#checkPropertyAccess(String)
  62:    */
  63:   String getArch();
  64: 
  65:   /**
  66:    * Returns the number of processors currently available to the
  67:    * virtual machine.  This number is subject to change during
  68:    * execution of the virtual machine, and will always be >= 1.
  69:    * The call is equivalent to {@link Runtime#availableProcessors()}.
  70:    *
  71:    * @return the number of processors available to the VM.
  72:    */
  73:   int getAvailableProcessors();
  74: 
  75:   /**
  76:    * Returns the name of the underlying operating system.  This
  77:    * is equivalent to obtaining the <code>os.name</code> property
  78:    * via {@link System#getProperty(String)}.
  79:    *
  80:    * @return the name of the operating system on which the VM
  81:    *         is running.
  82:    * @throws SecurityException if a security manager exists which
  83:    *                           prevents access to the name property.
  84:    * @see java.lang.System#getProperty(String)
  85:    * @see java.lang.SecurityManager#checkPropertyAccess(String)
  86:    */
  87:   String getName();
  88: 
  89:   /**
  90:    * Returns the system load average for the last minute, or -1
  91:    * if this is unavailable.  The availability and calculation
  92:    * of the load average is system-dependent, but is usually 
  93:    * a damped time-dependent average obtained by monitoring the
  94:    * number of queued and running processes.  It is expected
  95:    * that this method will be called frequently to monitor the
  96:    * average over time, so it may not be implemented on systems
  97:    * where such a call is expensive.
  98:    *
  99:    * @return the system load average for the last minute, or -1
 100:    *         if this is unavailable.
 101:    * @since 1.6
 102:    */
 103:   double getSystemLoadAverage();
 104: 
 105:   /**
 106:    * Returns the version of the underlying operating system.  This
 107:    * is equivalent to obtaining the <code>os.version</code> property
 108:    * via {@link System#getProperty(String)}.
 109:    *
 110:    * @return the version of the operating system on which the VM
 111:    *         is running.
 112:    * @throws SecurityException if a security manager exists which
 113:    *                           prevents access to the name property.
 114:    * @see java.lang.System#getProperty(String)
 115:    * @see java.lang.SecurityManager#checkPropertyAccess(String)
 116:    */
 117:   String getVersion();
 118: 
 119: }